instruction stringlengths 31 24.3k |
|---|
Should blue and white stars appear red and inflated while observed on the lower part of the night sky for the fairly same reason as the sunlight during sunset? As these stars emit blue light frequencies along with other frequencies the blue component should be scattered the most even for stars shown on the higher parts... |
The question is as follows:
For the core shown in Fig. 3.20, it is required to produce a flux of 2 mWb in the limb CD. The entire core has a rectangular cross section of 2cm × 2cm. The magnetizing coil has 800 turns. The relative permeability of the material is 1200. Calculate the amount of magnetizing current require... |
In most mathematics textbooks I have read (see e.g. Axler), the change of basis (COB) matrix has been introduced as a useful computational tool for expressing components of vectors in different bases. In mathematical physics texts (see e.g. Szekeres Chapter 3.6), these are referred to as passive transformations. It is ... |
In Steinhardt's bouncing cosmology model, during the contraction phase the Hubble radius shrinks to microscopic sizes, although the overall contraction of the universe is much less significant. Each patch of space subsequently undergoes normal expansion, and typically should display properties similar to our CMB.
Howev... |
Is there any physical reason/symmetry prohibiting me from studying the $e^-\rightarrow e^-\gamma$ interaction? Because I haven't seen any QFT textbook dealing with such a simple process. It is the simplest QED interaction, after all...
I have tried writing down a Feynman amplitude for such process
$$i\mathcal{M}=ie\bar... |
H = U + PV
G = H - TS
The definition of these state functions seems like a random combination of thermodynamic properties which just turn out to be state functions and independent of the path taken. Is there any convincing reason for why these functions are defined using the equations that they are? Or is this is just ... |
In the context of NMR (or in general qubits nowadays), a CP sequence is a refocussing sequence that looks like X/2 - X^n - X/2. A CPMG sequence instead is X/2 - Y^n - X/2. This change of axes is in fact the main contribution of MG, see https://aip.scitation.org/doi/10.1063/1.1716296 (or so I take from the abstract, I c... |
I saw that $1$ w/s is equivalent to $6.2 \times 10^{18}$ eV. But if that was true $1$ w/s or less could fully ionize any atom is that true?
|
So, we all know that if force is perpendicular to the displacement, then work done is 0. But to generate force, I have to use up some of my energy. Had the angle not been perpendicular, my energy would have transferred in increasing the velocity of the object but since the force angle is perpendicular, I wonder where m... |
Context of the question:
Schlosshauer (978-3-540-35773-4, p. 33) states:
"A useful intuitive way of quantifying the entanglement present in
this state [(1)] is to consider the following question: How much can
the observer learn about one system by measuring the other system?"
$$|\psi\rangle=\frac{1}{\sqrt{2}}\left(|\... |
I have a question regarding the math of General Relativity. Let's consider an observer with two clocks attached to their head and feet. If the person is in free fall, their feet would have a lower radial coordinate than their head. According to the calculation of the Schwarzschild metric, the clock at their head would ... |
I am working my way through Srednicki and am at Chapter 95 which introduces supersymmetry.
$\newcommand\dag\dagger$
In Chapter 95, Srednicki introduces the idea of a vector superfield, which he says is not subject to any constraints save for the fact that it's Hermitian.
Later when Srednicki comes to doing gauge transf... |
I just want to make sure my basic understanding of this is correct.
When the internuclear distance is finite, the symmetric wavefunction of the electron is lower in energy because it experiences a potential energy minimum. This potential energy minimum comes from the fact that because the electron can be at both proton... |
When we add a scalar field into AdS space time, under which limit can we ignore the gravitational back reaction? In the case of massless scalar, can we totally ignore the backreation to the background geometry?
|
I'm trying to understand the observations in IceCube Neutrino Observatory where they observe the Cherenkov radiation emitted by a charged particle in the ice. I know that applying the Huygens principle to spherically emitted radiation leads to a conic shaped radiation analogous to the Mach cone.
However, I don't intuit... |
I often see the term "volume of the gauge group" and I am not clear on what this is referring to. For example, in the second volume of Weinberg (page 22), he says
...the volume of the gauge group is just the volume of the global Lie group itself times the number of lattice sites."
but what is the volume of the global... |
Chapter 42 of the Feynman Lectures on Physics claims that a clock "higher up" in a gravitational field will tick more slowly, and that is used to argue that space-time in a constant gravitational field is curved. I think the argument consists of three steps, which can be summarized as follows.
Imagine two clocks, A at... |
I have a question relating to quantum mechanics that keeps coming back in one form or another, but it can be summed up most concisely in the context of the Hydrogen eigenstates.
When solving S.E. for hydrogen and separating variables, one arrives at a 2nd-order diff. eq. in the azimuthal component, where $f'' = -m^2f$.... |
I am studying QFT with Schwartz’s textbook and solving problem 3.2.
But I somehow getting struggled with differentiating the given lagrangian
$\mathcal{L} = \frac{1}{2}\phi(\Box +m^2)\phi$
I know that I need to get $$T^{\mu\nu} =\frac{\partial\mathcal{L}}{\partial\partial_\mu\phi}-g^{\mu\nu}\mathcal{L}$$ but I cannot d... |
Why can we detect the Microwave Background radiation (the earliest light that we can see) and not the light from stars beyond the observable universe? Should not the microwave radiation also be beyond what we can detect?
|
In a certain problem regarding motion of a particle in a gravitational field with axial symmetry, I have an expression of an effective potential $\Phi_{eff}(r,\theta)$. Now, I am interested to study the motion of the particle in the $r-\theta$ plane. Spherical coordinates $(r,\theta,\phi)$ is used in the problem and th... |
Several articles suggest, in a MOPA configuration high power fiber laser, the SRS can be mitigated by increasing the bandwidth of the OC FBG. How to determine the optimized bandwidth of such FBG? Does the bandwidth of the HR FBG is also related? What is the relationship between the bandwidths of the FBGs and the amount... |
Edit :- Sorry I didn't clarify before. My question is not duplicate. To be specific and understandable for all, please consider the voltage generator has a constant peak wattage, like a solar panel. I read this post https://www.blueraja.com/blog/194/do-transformers-obey-ohms-law and this is not the answer I was looking... |
If a (c/2)(m/s)*s long plane goes with c/2(m/s) velocity according to the observer on earth, and in the plane there are two light sources and observers that are positioned at both the tail and tip, I cannot understand how light traveling from tip to tail takes 0.5 seconds for the guy in the plane and much shorter for t... |
I’ve seen other posts throughout stackexchange that say a black hole may exhibit having a universe within/across it’s event horizon. does this make a black hole diplanar? or if not, is there a better way to label/describe this quality?
|
Let's say that we have an astronaut in space of length $L$ and mass $m$:
Because of some truly irresponsible space agency, they've attached jet engines to this fellow's arms as depicted in the picture. Assuming that our astronaut will stay completely rigid in his or her composure, such that in their non-intertial fram... |
I am currently working my way through "Special Relativity and Classical Field Theory (The Theoretical Minimum)" by Susskind and Friedman, and I'm a little bit perplexed by the interpretation of this picture being used to describe Lorentz Contraction:
The idea is that an observer in the x', t' frame observes a 1-unit l... |
I am currently practicing Physics questions in basic electrostatics and I am confused about why my teacher is randomly assigning V (potential energy) as 0 in random sides of two parallel plates (where E (electric field) is constant).
The question is asking that I find the total energy of a system where an electron ente... |
I am a Grade 12 physics student working on an assignment that involves calculating how changing the suspension length of a bifilar pendulum affects the period of the pendulum.
My teacher told me to use the equation T=2π√(l/3g). I have to include the derivation of the equation and I am struggling to find resources outli... |
If the bias current is approximately 2 Ic (double the critical current), wouldn’t the whole loop become normal? Or do only the Josephson junctions become normal? And when the junctions become resistive, how can you even have Cooper pairs (and thus have the loop be superconducting)? Is it because the bias current is be... |
I was really looking forward to the atomic physics portion of my quantum mechanics class and was pretty disappointed with Griffith's hand-wavey qualitative description that was scarcely above the chem101 level. I've seen several other great posts about Hund's rules on the forums but I want to ask about a rigorous demon... |
I bought this "flickering flame bulb" recently.
This is what it looks like:
https://www.youtube.com/shorts/Py7pD0Oor9o
Here is the same thing but in slightly slow motion:
https://www.youtube.com/shorts/bGrohhEwISg
I (a physics enthusiast) was talking about the bulb with my Dad (electrician) and we were arguing about ho... |
As title states. I am confused about this topic--what it actually means in practice.
|
I got a problem where I had to calculate the equation of state of a scalar factor $a\propto t^q$. I found that, solving the Friedmann equation, $\rho_\Phi=\frac{3M_p^2q^2}{t^2}$, which is equal to $\rho_\Phi=\frac{1}{2}\dot{\Phi}^2+V(\Phi)$, so you can get $p_\Phi=\rho_\Phi-2V(\Phi)$, and finally, after substituting $\... |
I am not a 100 percent sure this is the best stack exchange for this question, but I couldn't think of a better stack exchange website. I was inspired to ask this question because I have been wondering whether the universe we live in is a simulation in some higher universe which has different laws of physics. Let us ju... |
My professor asked me this and I haven't been able to find an answer. I know that entropy is constant in reversible processes like an adiabatic one, but in that case, the internal energy is also conserved.
Any ideas?
|
Suppose you have a rigid body and you have two local coordinate systems on the body at $P_1$ and $P_2$ and we can write a vector in the $P_2$ coordinate system using $P_1$ via the transformation $v_{p2} = R*v_{p1} + T$.
We know the instantaneous angular velocity vector of the object written with respect to $P_1$, how d... |
I am reading this paper (or this link), and I'm troubled by the custodial transformation. So, I will use the notations and equation labels appearing in this paper.
If we write the Higgs field into the four real components
$$
\Phi=\left(\begin{array}{c}
-\operatorname{Re} \phi_1 \\
\operatorname{Im} \phi_1 \\
\operatorn... |
In calculating the ground state of atoms or molecules at the equilibrium geometry, the expectation values of the kinetic, $⟨T⟩$, and potential, $⟨V⟩$, energies relate to the total energy, $E$, according to the virial theorem:
$$
E=−⟨T⟩=\tfrac{1}{2}⟨V⟩.
$$
Since the solution of the Schrödinger equation at the Hartree Fo... |
I was reading the second edition of "THERMODYNAMICS AND AN INTRODUCTION TO THERMOSTATICS" by (late) Herbert B. Callen which states
(Furthermore) the delivery of work (and of heat) is identical for every reversible process.
Could this be interpreted as work and heat being state variable (or functions) for reversible p... |
I've been reading on Jia-Ming Liu's Photonic Devices and I came across this part:
I don't understand the highlighted part: in a TE mode we know that $E_z=0$, but the other components may be non-zero. Since $\epsilon$ lies in the $(x,y)$ plane, then so does $\nabla \epsilon$. With this information alone, it is impossib... |
One can show that, in the interacting theory, the operators that create single-particle energy-momentum eigenstates from the vacuum are
\begin{align}
(a_p^{\pm\infty})^\dagger=\lim_{t\to\pm\infty}(a_p^t)^\dagger\tag*{(1)}
\end{align}
where
\begin{align}
(a_p^t)^\dagger=i\int{\rm d}^3x\,e^{-ipx}\overleftrightarr... |
I'm currently writing a numerical code to solve the quantum system (in 3D) with an attractive ($v_0 < 0$) Gaussian potential,
$$ V(r) = v_0 \exp(-r^2/r_0^2). $$
It would be nice to have some reference values (at least for the energies) to compare to and to test my accuracy. Does anyone know of any article/textbook whe... |
I am searching for a reference I read and then misplaced, in which Weinberg asserts that the Dirac equation's prediction of the positron is a characteristic of any equation which has the general form of Dirac's- in other words, the prediction of the positron does not uniquely prove the validity of the Dirac equation. A... |
I saw in a video that static pressure is simply hydrostatic pressure which is due to weight of fluid but when we see in venturimeter, fluid rises in capillary tube due to static pressure. My question is that why fluid rises up while static pressure is due to its weight and there shouldn't be pressure in uppermost poi... |
I am reading the first chapter of "Statistical Theory of Fields" by Kardar. There he discussed the idea of phonons.
Consider an ideal lattice at zero temperature with lattice vectors $\vec q^*(l,m,n)=[l\hat a+m\hat b+n\hat c]$
Small fluctuations about the ideal positions (due to finite temperature or quantum effects) ... |
When the balloon rises and the pressure on its outer surface decreases, does the inner pressure also decrease? If Boyle's law holds true in this case, then the pressure of the gas inside the balloon decreases since its volume increases. However, were that the case, does the pressure inside equal the pressure outside, i... |
I have read that polarized light is treated by Jones vectors and that to treat partially polarized light you have to use Stokes vectors.
But in some treatment I saw the Jones vector $E=[\sqrt{\frac{1+d}{2}},\sqrt{\frac{1-d}{2}}]^\intercal$ be used to describe a partially polarized light with degree of polarization $d$.... |
I have been attempting to go through Chapter 12 of Peskin & Schroeder, but I have been having a very tough time. In particular I have been having trouble following this chapter much beyond page 397 beginning with integrating out high momentum degrees of freedom.
In Section 12.1, they start with the following generating... |
So there's this equation:
$dU_{V,S}≤0$
which comes from
$dS≥\frac{dQ}{T}$
$dQ = dU$ since isochoric
$dS≥\frac{dU}{T}$
$TdS≥dU$
$dU≤0$ if $dS=0$
Firstly, are these set of equations valid? If so, how can the internal energy of a system decrease if there is no work done and no change in entropy? I'm having a hard time wra... |
In the SSH model for the 1D case, we get the eigenvectors as $$|(\pm)k>= \begin{pmatrix} \pm e^{-i\phi} \\ 1 \end{pmatrix}$$ where $\phi = tan^{-1}(\frac{wsin(k)}{v+wcos(k)})$. We can calculate the Berry connection as $i<k|\frac{d}{dk}|k>$, but I don't know how they get it equal to $-\frac{1}{2} \frac{d\phi}{dk}$. Can ... |
Let us consider a sphere made of a linear, homogeneous and isotrope dielectric with constant $\epsilon_r$ which is inserted in a vacuum where a uniform electric field $\underline{E}_0$ was applied (now it has obviously been distorted by the field $\underline{E}_r$ exerted by the polarized sphere). Say we want to find t... |
The spacecraft with the same physical properties is moving in space. Let's assume that there are no resistance in space.
A stationary observer observes a spacecraft whose speed varies from 100 m/s to 120 m/s.
An observer moving at 100 m/s in the opposite direction to the spacecraft observes the situation 1. (The rela... |
Given a static spherically symmetric spacetime with metric being solution for interior of perfect fluid sphere $$ds^2=e^{2\nu}c^2dt^2-e^{2\lambda} dr^2-r^2 (d\theta^2+\sin{\theta}~d\phi^2) \tag{1}$$ is the hyperspace defined by equation $${e}^{2\nu}(r_0)=0\tag{2}$$ a trapped surface, apparent horizon or event horizon?
... |
Kinetic energy is relative and depends upon the observer because velocity depends upon the frame of reference. However, we have an absolute temperature scale. How is this possible if temperature is the measure of (average) Kinetic energy ?
|
It is my impression that verifying a symmetry in physical laws often takes the form of verifying the corresponding conservation law instead. But since experimental verification must allow for quantitative errors, I see three possibilities:
There is a version of Noether's theorem that says an approximate symmetry corre... |
Let's say a current is passed through a load (or more precisely, a source of resistance), then will the emerging electrons have less energy and less velocity with what they had entered the resistor?
Also, if the electrons emerge with a less velocity, won't there be an accumulation of them inside the resistor and thereb... |
Can neutral object move when it develop opposite polarity during process of induction as electron move in the object from end to another.
If not, then why does small pieces of paper get attracted and move towards scale when we charge the scale by rubbing it?
|
With DC, for example, a battery, it's easy to understand that one terminal is more negatively charged then the other, so that there is a potential difference between the terminals, which creates a voltage between them, so that if we connect a conductive material, current will flow.
It's harder for me to understand the ... |
I did all the courses on Quantum Mechanics and QFT which my faculty offers and up to now no one defined to me what a Heisenberg-Weyl algebra actually is.
This appears in my studies when studying the polymer representations in QM.
So the points not clear to me are:
What is and why is it important the Heisenberg-Weyl Al... |
Suppose a rigid body is lying in space with no external forces. Now when a force is applied on it, the force can introduce either a translation when applied towards the center of mass or both translation and rotation when off the center of mass, and for the same force the linear acceleration will be same. But how does ... |
Hi I am new to solid state physics and am reviewing a prior knowledge section and would like some clarification. The following appeared in the course notes:
From my understanding, Eigenstates are only eigenstates when associated with the appropriate operator. Are the terms Eigenfunction and Eigenstate analogous? I und... |
I have been confused by how voltage is measured in joules per coulomb, until I thought of it in the context that the coulombs aren't measuring charge, but instead are measuring how many electrons are being moved. Is this a correct conculsion?
|
While this is inspired by science fiction, if I have a hypothetical laser weapon that needs to meet a very high energy requirement of energies of the order $ 1 \times 10^{22} $ Joules, what formula would describe the power of the laser as a function of distance with attenutation and beam divergence taken into account? ... |
I am always confused with the algebra of differentiating the index notation, and have browsed many other posts but still confused. There must be details I have been missing. It would be really appreciated if anyone could answer my questions.
My questions are:
What is the differentiation rule for $\partial^2$?
What is... |
I need an equation for calculating the penetration depth of a projectile in a non-homogenous material. I have the values for density of each layer and the projectile, speed, and angle. Does anyone know of a good one?
|
While reading a published paper, I read that some photons were being detected at the arm of a Michelson interferometer which was intended and set to have approximately perfect deconstructive interference. This was ultimately attributed to imperfect alignment and optical equipment. The paper also said that the experimen... |
So we say that charge on a conductor resides on the surface, so why is that so, and I heard some explanation saying that because electric field inside the conductor is zero. But why is that so?
|
In Ashcroft and Mermin's Chapter 1, the equipartition theorem is often used to evaluate the mean speed of an electron in an (ideal) electron gas treated with classical statistical mechanics. That is, it is often written that
$$ \langle{v}\rangle = \sqrt{3kT/m}.$$
However, strictly speaking, equipartition of energy tell... |
In quantum mechanics, unitary projective representations play a crucial role. To be more general, I want to pose the question in sense of projective representations, then everything would follow as a special case for unitary projective representations.
A projective representation is a group homomorphism $\theta:G \to \... |
In Ashcroft and Mermin, they use the thermodynamic identity
$$P = -\left(\frac{\partial E}{\partial V}\right)_N$$
to compute the pressure of an electron gas. Is temperature $T$ also held fixed here?
|
https://en.wikipedia.org/wiki/Lichtenberg_figure
I cannot find anywhere online what the result would be if I used, for example, 1GeV compared to the 10-20MeV which are usually used. This is all theoretical, and clearly, I don't have access to such a high-voltage appliance, I'm just curious.
Is it possible to predict, o... |
Some very short-lived nuclides (sometimes called 'resonances') are nevertheless considered to have actually existed, if only very very briefly....
How do nuclear physicists know the isotope actually existed at all?
Is there some particle(s) released by the extremely ephemeral nucleus that otherwise would not have been ... |
A freely falling body in a gravitational field does not feel any force. Does the same thing apply for electric attraction?
That is, consider a light body with a large positive charge and an electron accelerating towards it due to electric attraction. Will the election feel any force?
We are assuming that gravity can be... |
Some nuclear isomers (like tantalum-180m) have never even been observed to decay....
How do we know it is in an excited state then? That it actually absorbed some form of energy?
Can these includes be induced to decay and emit a gamma ray, even if they never spontaneously do so?
|
The header of the problem asks us to calculate the entropy change $\Delta S$ (in the universe) when heating an iron block from $T_1$ to $T_2$, knowing its heat capacity $C_V$. Is it possible to determine $\Delta S$ with just this information?
I have read in other threads (e.g.) that we should just be concerned about th... |
Is the tangent space of a one-dimensional smooth manifold always trivial, i.e. is $TM \cong M \times R$?
|
Consider the 3D $\mathcal{N}=2$ superspace covariant derivatives $D_\alpha$ and $\bar D_\beta$, which have the following anti-commutation relations
$$\{ D_\alpha, \bar D_\beta \}=-2i \gamma^\mu_{\alpha \beta} \partial_\mu$$
$$\{ D_\alpha, D_\beta \}=0$$
$$\{ \bar D_\alpha , \bar D_\beta \} = 0, $$
where $\alpha= 1,2$ a... |
One way of deriving the Euler-Lagrange equations is to require that the action integral is stationary under a virtual displacement $\delta S=0$. One then usually arrives at the equation
$$
\delta S=-\left[\frac{\partial L}{\partial \dot q}\delta q\right]_{t_1}^{t_2}+\int_{t_1}^{t_2} dt\left[ \frac{\partial L}{\partial ... |
The sun sends out unpolarized light. There are infinite degrees in which these photons are oriented. A polarizer only lets in light of one specific orientation.
In statistics, the infinitesimal area/slice of a single value in a continuous probability distribution is virtually meaningless, but I'll call it zero.
How can... |
I have been studying the Landau theory for critical second order phase transitions.
I am looking for a specific and detailed treatment of a liquid-gas phase transition near the critical point. Many treatments I have seen default to the example of magnetization. For example in Chapter 8 and then 13 of Peskin & Schroeder... |
I’m trying to figure out if $\left< a \middle| b \right> = \left< b \middle| a \right> $ when $\left| a \right>$ and $\left| b \right>$ are eigenfunctions with the same eigenvalue $\lambda$. I tried a few vectors and it seems to be correct, but is it general? If not, is there any extra conditions needed for this to be ... |
Why varying the frequency of a propagation wave in a non-dispersive media doesn’t change it’s propagation velocity?
Before anything, I want to note that I’ve seen already similar questions on this site but none have the perspective I give it to it. It may sound as a dumb question since I’ve learnt by heart that the p... |
As far as I know, there's no rule that planets should orbit stars, just that a planet which happens to be moving with orbital speed relative to a star will end up orbiting it. My question is if the same thing is true for the orbit of a star around the barycenter of the system. Intuitively it would be the same, meaning ... |
Let's say for a specific simple decoherence model you end up with the following density matrix for the "system" (I will use the common separation in "system" and "environment" usually used in decoherence literature):
$$\frac{1}{2} \begin{pmatrix}1&r(t)\\ r^*(t)& 1\end{pmatrix}$$
with $r(t)=e^{-2i\omega t}$ ($\omega$ be... |
I have read that a magnetic field consists of photons or virtual photons. For a given magnet, if the field emanating from one pole was examined vs that of the other pole, is there some observable difference between the way the components of the two fields behave or a difference between the behavior or type of these pho... |
I am attempting to numerically solve a BVP for a solid core solenoid field. I am starting with:
$\vec{\nabla{}^2}\vec{A_r}=0$
$\vec{\nabla{}^2}\vec{A_\phi}=\frac{\mu}{\mu_0}\vec{J_\phi}$
$\vec{\nabla{}^2}\vec{A_z}=0$
in cylindrical coordinates where the current $J$ is traveling along a cylindrical surface in the $\phi$... |
Consider an $SU(2)$ doublet of bosons $\Phi = (\phi^+, \phi^0)^T$, where the complex scalar field $\phi^+$ destroys positively charged particles and creates negatively charged ones, and the complex scalar field $\phi^0$ destroys neutral particles and creates neutral anti-particles. The theory has $SU(2)\times U(1)$ sym... |
For example, Wikipedia says:
The existence of the electroweak interactions was experimentally established in two stages, the first being the discovery of neutral currents in neutrino scattering by the Gargamelle collaboration in 1973, and the second in 1983 by the UA1 and the UA2 collaborations that involved the disco... |
Set up:
There's a block of mass $M$ connected to a spring of negligible mass. This is set up horizontally, and there is no friction between the block and the surface. The block oscillates with simple harmonic motion, with an amplitude $A$.
Case 1:
A piece of clay of mass $M$ (the same mass as the block) is dropped on t... |
I know that deep learning (especially CNN) is used in many physics studies nowadays.
For example, it is used to distinguish whether the pulse read by the oscilloscope is fast neutron or gamma.
Its performance is quite good.
But at the same time, I've heard that some people are skeptical of using deep learning in physic... |
I was asked to evaluate whether the following reaction is possible or not:
$$\Sigma^0 \rightarrow \Lambda + \pi^0$$
I have evaluate all conservations law that could prevent it to occur, but i haven't find it! In fact, when i checked the answer, it seems that the reaction does not conserve energy. But i can't understand... |
I've heard compelling reasons to think that it is one although why do we assert this in light of the calculation which shows a point particle creates an electrostatic field of infinite energy (see e.g. Griffiths ED 2.4.4 or Feynman Lectures vol. 2 section 28)?
Why do people not consider this calculation a definitive re... |
Suppose the volume of a cylinder with diameter $d=$11.92 ± 0.01 mm and height $h=$38.06 ± 0.02 mm. Calculating $\frac{\pi d^2h}{4}$, the volume is 4247.282773 mm^3, without rounding off. Now, I read that "The rule in multiplication and division is that the final answer should have the same number of significant figures... |
$\renewcommand{\vec}{\boldsymbol}$
$\newcommand{\highlight}{\boxed}$
9.5.3 Velocity and Acceleration in a Rotating Coordinate System
Applying Eq. (9.8) to the position vector $\vec{r}$, we have
$$\left(\frac{d\vec{r}}{dt}\right)_{in} = \left(\frac{d\vec{r}}{dt}\right)_{rot} + \vec\Omega\times\vec{r},$$
or
$$\vec{v}_{i... |
I was solving a question which asked the uncertainty in velocity of an electron trapped in a cube of length x.
Well in the solution they have taken the uncertainty in position to be length of the body diagonal, my doubt is why is the length of the body diagonal the uncertainty, or is the solution wrong ?
|
For example, the equation (under constant pressure) $$dH=C_p\, dT$$
is integrated to $$\Delta H = \int^{T_f}_{T_i} C_p \, dT $$.
What is the difference between the $dH$ and $\Delta H$?
|
I am using tight binding approximation for a 2D material by 2*2 Hamiltonian, and I have ploted the density of states correctly. Can I also calculate the partial density of states using tight binding? What is the method?
|
In establishing ADM or 3+1 decomposition, one starts with choosing a foliation $\Sigma_t$ where t is a scalar function and $\Sigma_t$ is demanded to be a spacelike slice, i.e. with time-like normal vector field.
In the case of Schwarzschild black hole, the constant time slice (coordinate $t$ in Schwarzschild metric) se... |
Consider a scenario where a particle is placed on the surface of a dome-shaped object (a hemisphere) and moves on the surface of the dome due to gravity. My question was, how do I find the equation of motion of the particle using Lagrangian mechanics (assuming the motion is two-dimensional and looks something like Fig ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.